2) Some models allow you to set teh value of threat to 0 or near zero so it's almost accomplishing what you want

3) Why do you not care about threat? Threat is an essential part of tanking. If you can't push out enough threat to keep up with DPS'rs (especially warlocks and Arms/Fury Warriors) then the gear doesn't do you a whole lot of survivability work cuz the boss
will want to hit them instead.

There are a few situations where you don't care about threat (tanking Steelbreaker, tanking Kologarn body in most cases, tanking Freya, etc). Be very careful of how much you think you have "enough" threat. It's easy to gear/gem yourself to completely
ignore it, and suddenly find yourself being caught by DPS all of a sudden (aka, all PvP gear, and stam gems might not be the best way to go).